Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related deaths worldwide. Although surgery can cure some early-stage resectable patients, the postoperative recurrence rate remains as high as 30%-55%. Perioperative immune checkpoint inhibitor (ICI) therapy, which includes "neoadjuvant" therapy before surgery and "adjuvant" therapy after surgery, has significantly improved survival outcomes in resectable NSCLC patients. Large clinical studies, such as CheckMate 816, have demonstrated the superiority of neoadjuvant ICIs combined with chemotherapy in increasing the pathological complete response rate (pCR) and prolonging event-free survival (EFS). However, even with these advanced treatments, some patients do not achieve long-term benefits and experience early recurrence. This paper reviews the latest research progress of perioperative ICIs in NSCLC treatment, particularly the effectiveness of neoadjuvant chemoimmunotherapy in improving pCR and extending EFS. It further explores the recurrence patterns, resistance mechanisms, and potential biomarkers in NSCLC patients after neoadjuvant immunotherapy. By integrating basic research and clinical data, we analyze the mechanisms of early recurrence following perioperative immunotherapy and discuss future research directions and therapeutic strategies, providing new insights into precision treatment and recurrence prevention for NSCLC patients.